The Roddick (L.78) occurrence is located west of the south branch of Siwash Creek, approximately 3.6 kilometres east-south east of its creek mouth on the Fraser River.
The Siwash Creek area is underlain by Early and Middle Jurassic Ladner Group argillite, siltstone and greywacke and Permian to Jurassic Hozameen Complex chert in contact along the Hozameen fault, a major, steeply dipping, north-northwest –trending fracture system extending from northern Washington State to the Fraser River. Most of the mineral occurrences in the area lie east of, but generally close to, this fault, which encloses metaplutonic rocks of the Coquihalla serpentine belt between Mount Dewdney and Siwash Creek. The Ladner Group and, to a lesser extent, Hozameen Complex rocks are cut by a variety of small intrusive bodies ranging in composition from gabbro through granodiorite to syenite.
Geology near the confluence of the north, middle and south forks of Siwash Creek is characterized by poorly to moderately-bedded, dark coloured, pyritic slatey argillite locally intercalated with thin beds of greywacke and siltstone, all assigned to the Ladner Group. These rocks have been intruded by locally altered, light- coloured, felsic sills and dikes.
Gold is spatially associated with feldspar porphyry sills in the area of the Roddick occurrence. Many of these sills have irregular chilled margins; narrow aureoles of weak thermal alteration are developed in the host argillite. Locally, the sills are fault-bound and their contacts marked by rust-stained quartz veins up to 60 centimetres wide. Many sills are also cut by irregular quartz stringers, quartz-filled tension gashes or intersecting sets of quartz veins up to 5 centimetres wide. These veins contain small vugs lined with quartz crystals and sparse disseminated pyrite. Fine gold reportedly occurs both in the quartz and the intrusions and is generally coated with a film of iron oxide (Bulletin 79, page 62).
The Roddick occurrence was discovered in 1890, the first of many occurrences eventually located in the Siwash Creek area. Underground exploration was carried out in several adits and by 1895, the property received Crown-grant status. Narrow lenses and stringers of quartz cut a 7.5-metre wide "porphyry dike" and the surrounding slates reportedly carried iron oxides and free gold. In 1934, a 10 metre crosscut was driven to intersect a 5 to 25 centimetre wide, heavily oxidized quartz vein striking 130 degrees and dipping 25 degrees to the southwest. This vein is described as being hosted by slates just east of the porphyry dike.
In 1980, Aquarius Resources prospected and soil sampled the area. In 1998, Hillsbar Gold completed a program of geological mapping and geochemical sampling on the area as the Mike claim. In 2012, New Carolin Gold completed airborne magnetic and radiometric surveys, totalling 759 line-kilometres, on the area.
